Recently, a photoplethysmography (PPG) sensor has been gradually installed in many wearable devices to detect and measure the health related information, such as cardiac rhythm, blood oxygen, etc.
Referring to FIG. 1, an existing optical biosensor module 1 includes a printed circuit board (PCB) 11, a light receiver 12 and a light emitter 13 both disposed on a same plane 111 of the PCB 11, and a light blocking wall 14 formed between thereof. However, when this kind of optical biosensor module 1 is installed on a wearable device, it will be difficult to further miniaturize the wearable device.
How to improve the structure of the optical biosensor module 1 so that the size of the wearable device can be thinner is a problem to be resolved by skilled persons in this art.